Consider using nf-schema plugin to validate inputs

[jashapiro]

Is your feature request related to a problem? Please describe.

We currently do some parameter validation and value checking, but we could do more, which might help with usability

Describe the solution you'd like

We should explore using the nf-schema plugin to validate parameters and sample data. See https://nextflow-io.github.io/nf-schema/latest/nextflow_schema/sample_sheet_schema_specification/

Describe alternatives you've considered
More manual validation checks...

Additional context

I think this should be compatible with the nextflow-schema.json file that we have already added, but we would need to add schema files for the sample sheets as well. We should be able to use the included samplesheetToList function to read in our data files and convert them to usable formats.